抑制素免疫与超数排卵

寻找一种简单的繁殖技术以提高排卵率或用作超数排卵是长期以来的目标。虽然利用促性腺激素的超排技术已成为获得可移植胚胎的有效手段,但仍有许多问题尚未解决。最突出的问题是:外源促性腺激素处理后个体差异较大,甚至出现ＰＭＳＧ处理后大卵泡不排卵的报道[1]。近年来国内外学者发现抑制素对垂体ＦＳＨ具有负反馈调节作用,认为内源性抑制素的抑制可能缓解这些问题,因而在促进动物多产和超排的研究中开始关注抑制素及其免疫中和技术[2,3,4]。1　抑制素特性抑制素(Ｉｎｈｉｂｉｎ,ＩＮＨ)是一种由动物性腺分泌的糖蛋白激素,是由α、β两个亚…     

抑制素免疫对羊生殖的影响

抑制素是一种主要由动物性腺（睾丸的支持细胞和卵巢的颗粒细胞）分泌的一种异二聚体糖蛋白激素,由两个二硫键连接两个不同的亚单位（α和β）构成。抑制素对垂体ＦＳＨ的分泌和／或合成具有选择性地抑制作用。抑制素免疫中和技术能特异性地刺激ＦＳＨ分泌,进而促进配子生成,提高动物繁殖力。西方把抑制素免疫对羊排卵率、产羔数、初情期、超数排卵和公羊繁殖性能的影响作一综述。     

抑制素及其对动物繁殖的影响

抑制素是二聚体糖蛋白激素,是机体分泌的一种能够调节促性腺激素分泌的活性物质,能够提高家畜的排卵率和繁殖力。抑制素抗原免疫可以提前动物发情,有效提高雌性动物的排卵率,对雄性动物生殖功能也起到重要的作用,因而研究抑制素对动物繁殖的影响,对于提高动物的生殖潜力有着很好的应用前景。     

抑制素免疫对繁殖调控的影响

抑制素是由动物性腺分泌的异二聚体蛋白激素，它通过选择性抑制垂体促性腺激素（主要是FSH）的分泌，进而影响动物的生殖活动。而利用抑制素对动物主动或被动免疫，可增加排卵率，提高繁殖力的独特功能越来越受到人们的重视。本文就近年来有关抑制素免疫对动物生殖功能影响的研究作一综述。     

抑制素免疫的研究进展

抑制素是机体分泌的一种能够调节促性腺激素分泌的活性物质.通过抑制素免疫中和技术能够解除抑制素对FSH分泌的抑制作用,从而促进排卵.本文对抑制素及其免疫机理、免疫方法、免疫对动物繁殖性能影响的研究进展作一综述.     

抑制素免疫的研制进展

抑制素是机体内分泌的一种能够调节促性腺激素分泌的活性物质，通过抑制素免疫中和技术能够解除抑制素对FSH分泌的抑制作用，从而促进排卵，本文对抑制素及其免疫机理，免疫方法，免疫对动物繁殖性能影响的研究进展作一综述。     

母猪性发育及性周期过程中外周血浆LH、FSH的分泌模式

母猪的性发育和性周期受到下丘脑－垂体－卵巢轴的调节，虽然下丘脑起着主宰作用，却受到主要由卵巢和腺垂体分泌的生殖激素的影响。ＬＨ、ＦＳＨ是由腺垂体分泌的促性腺激素，在调节性发育和性周期的过程中起着重要的作用。自从激素的放免方法建立以来，已能观察到性发育和性周期中促性腺激素的动态变化。１　性发育过程中ＬＨ、ＦＳＨ的分泌胎儿是非常活跃的激素生产单位，胎儿内分泌活动对分娩产生决定性的作用。妊娠晚期胎儿体内合成大量促性腺激素，并且带到出生后，因而仔猪刚出生后血浆中ＬＨ、ＦＳＨ浓度很高。Ｐｏｎｚｉｌｉｕｓ等…     

抑制素免疫与家畜繁殖

抑制素是机体分泌的一种能够调节促性腺激素分泌的活性物质,它能够提高家畜的排卵率和繁殖力.作者对抑制素及其免疫机理、免疫方法和免疫对家畜繁殖性能影响的研究进展进行了概述.     

卵泡抑制素主动和被动免疫及其基因免疫研究进展

抑制素是由动物卵巢颗粒细胞或睾丸间质细胞分泌的糖蛋白激素，对垂体ＦＳＨ的分泌具有抑制作用。用抑制素或其片断主动或被动免疫可以提高家畜的排卵率和产仔籽；用抑制素基因免疫可望得到类似效果。本文通过分析抑制系的理化特性。生物学作用及作用机制，主动和被动免疫对家畜繁殖力的影响，阐述了抑制素基因免疫的原理与方法及应用前景。     

太湖猪高繁殖力内分泌学机制的研究进展

综述了太湖猪高繁殖力内分泌学机制的研究进展,结果表明太湖猪促黄体素（ＬＨ）促卵泡素（ＦＳＨ）的高含量以及ＦＳＨ分泌对抑制素的抑制效应较不敏感,尤其是ＦＳＨ的高含量,很可能是太湖猪高排卵率的重要因素之一。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein